Revert 25960:6bf8b882df8f (x86: default-disable MWAIT-based idle driver ...)

The problem this was working around should be resolved with c/s
25961:6a5812129094 (x86/HPET: don't disable interrupt delivery right
after setting it up).

diff --git a/xen/arch/x86/cpu/mwait-idle.c b/xen/arch/x86/cpu/mwait-idle.c
index e8b26e4ec8759c5f2932cff2bf7ab346cf2c3a0b..6a9ca95d33b36c52d54ec4fce54ffa91ffe6d070 100644 (file)
--- a/xen/arch/x86/cpu/mwait-idle.c
+++ b/xen/arch/x86/cpu/mwait-idle.c
@@ -71,7 +71,7 @@
 # define pr_debug(fmt...)
 #endif
 
-static __initdata s8 no_mwait_idle = -1;
+static __initdata bool_t no_mwait_idle;
 invbool_param("mwait-idle", no_mwait_idle);
 
 static unsigned int mwait_substates;
@@ -500,13 +500,6 @@ int __init mwait_idle_init(struct notifier_block *nfb)
        if (pm_idle_save)
                return -ENODEV;
 
-       /* XXX The no-ARAT case is supposedly being taken care of, but at
-        * least some systems without ARAT hang for some reason, apparently
-        * only when using HPET broadcast mode (PIT broadcast mode seems to
-        * be fine). */
-       if (no_mwait_idle < 0 && boot_cpu_has(X86_FEATURE_ARAT))
-               no_mwait_idle = 0;
-
        err = mwait_idle_probe();
        if (!err) {
                if (!boot_cpu_has(X86_FEATURE_ARAT))